1. Field of the Invention
The present invention relates to an automatic screen printing process and apparatus. More particularly, the invention relates to a process and apparatus for manufacturing various kinds of high quality printed products in small lots automatically and stably without performing troublesome manual operations.
2. Description of the Prior Art
According to the conventional manual printing method, a fixed printing stand of a horizontal or inclined type having a length of 25 to 60 m is employed, stencil frame positioning fixtures are attached to the stand at intervals corresponding to the repeat length of a design for moving the stencil frames in the lengthwise direction precisely along the same length, and the operation of moving the stencil frames and the printing operation are carried out in sequence manually based on these positioning fixtures.
In this method, a plain cloth is applied to the surface of the printing stand while manually moving the cloth, and the printed cloth is dried on the printing stand or the printed cloth is once peeled from the printing stand and is then dried in the state hung from a ceiling. After peeling of the printed cloth, the top face of the printing stand is manually washed with water or it is washed with water by means of a simple movable water-washing machine, and after removal of water and application of a paste, a subsequent plain cloth is applied to the surface of the printing stand and the printing operation is then conducted. By repeating such cycle of operations certain times, printing of one lot is completed.
According to the conventional screen-running type semiautomatic printing method, a printing stand similar to the printing stand used in the manual printing method is employed and rails are laid out on both the sides of the printing stand for travelling printing unit-running stands, and fixtures for travelling the running stands in the lengthwise direction of the printing stand in parallel to said rails and precisely positioning the running stands having stencil frames attached thereto are attached to the printing stand at intervals corresponding to the repeat length of a design and a roll of a plain cloth is applied to the surface of the printing stand. Thus, the running stands travel automatically or manually to perform the printing operation, and after completion of the printing operation, the printed cloth is dried on the surface of the printing stand by a movable drying machine or the printed cloth once is peeled from the surface of the printing stand and is then dried in the state hung from a ceiling.
Then, the surface of the printing stand is washed with water manually or by using a movable water washing machine, and after removal of water, a subsequent plain cloth to be printed is applied to the surface of the printing stand. Thus, the above procedures are repeated certain times and printing of one lot is completed.
As will be apparent from the foregoing illustration, not only the manual printing method but also the screen-running type printing method involves a number of manual operation steps and the efficiency of the printing operation is very low. Further, since plain cloths are separately applied every time one cycle of the printing operation is completed, deviations of the quality are conspicuous in printed products of one lot and various disadvantages are caused by such deviation of the quality.